Solid Complexes Research Articles

Study of Luminescence Phenomena of Tb (III) Containing Fluroquinoline for Application in Optoelectronic Devices.

This study presents a series of six vivid green Tb(III) complexes, denoted by the general formula [Tb(L)3.secondary sensitizers], where L represents 1-cyclopropyl-7-(4-ethylpiperazin-1-yl)-6-fluoro-4-oxoquinoline-3-carboxylic acid and secondary sensitizers consist of heterocyclic N-donor aromatic systems. The synthesis of these complexes were achieved through a solvent-assisted grinding method, and their characterization involved various techniques such as CHN analysis, FTIR, NMR, UV, XRD, and NIR spectroscopy. These analyses confirmed the successful synthesis of complexes with coordination between the quinoline moiety and the metal ion. Photoluminescence studies were conducted in solid and solution phases, revealing excellent luminescence properties. The bright green color emitted by the complexes upon exposure to UV rays was attributed to the hypersensitive 5D4 → 7F5 transition. J-O analysis indicated an asymmetrical coordination environment around in the complexes. Additionally, various radiative properties (Ared, Anred, η, βexp, σs) and band gap values were determined, highlighting the potential applications of these complexes in diverse optoelectronic fields. Chromaticity evaluation demonstrated high color purity in both solid and solution phases. Furthermore, the CCT value identified the solid complexes as a cool light source. Overall, the analyses supported the exceptional luminosity of synthesized complexes, positioning them as promising luminescent materials for a wide range of devices.

Synthesis, Structural Characterization, Optical Properties, and Biological Potency of Co(II), Cu(II), and Cd(II) Complexes With Heterocyclic Thiosemicarbazide Ligand: Insights From Molecular Docking Studies

ABSTRACTA novel heterocyclic thiosemicarbazide ligand, [(Z)‐N‐(2‐oxoindolin‐3‐ylidene)nicotinohydrazide] (H2L), and its Co(II), Cu(II), and Cd(II) metal chelates were synthesized and characterized using a variety of analytical methods, including elemental analysis, FT‐IR, UV–Visible spectroscopy, EI‐mass, fluorescence spectroscopy, X‐ray powder diffraction, and TGA. The structures and geometries of the complexes were determined using these methods as [Co2(H2L)2Cl2(H2O)4]·2H2O, [Cu(H2L)2Cl2(H2O)2]·2H2O, and [Cd(H2L)2Cl2(H2O)2], all having octahedral geometry. The particulate diameters for [Co2(H2L)2Cl2(H2O)4]·2H2O, [Cu(H2L)2Cl2(H2O)2]·2H2O, and [Cd(H2L)2Cl2(H2O)2] were 192.68, 68.48, and 192.74 nm, respectively using Debye–Scherrer equation and FWHM approach. The corresponding FWHM values were 0.0078, 0.0217, and 0.0075, whereas the crystal strain was calculated as (ε) = 0.0018, 0.0056, and 0.0054, and the dislocation density (δ) as 2.69 × 10−5, 2.13 × 10−4, 2.69 × 10−5 Å−2. Quantum chemical calculations for the ligand and its solid metal complexes were carried out utilizing DFT with the DMOL3 module. Furthermore, the optical sensing response of the free ligand H2L to Co(II), Cu(II), and Cd(II) ions was investigated, revealing that the presence of these metal ions enhanced the fluorescence spectra of the ligand. Additionally, the antibacterial effects of these compounds, as well as their cytotoxicity in human cancer cells, were investigated. Compared to its metal complexes, the ligand, H2L exhibits increased antibacterial activity against various bacteria. Tests on HepG‐2 and MCF‐7 cells were conducted to evaluate the compounds' anticancer efficacy against the standard, Doxorubicin. The ligand, H2L, demonstrated greater cytotoxicity against the HepG‐2 cell line than its metal complexes. Docking experiments were conducted to assess the interaction of the ligand and its complexes with HepG‐2 (PDB ID: 2OH4) and MCF‐7 (PDB ID: 3W2S) cells, using the XP glide technique and Schrödinger suite software.

Preparation and characterization of solid lipid nanoparticles phospholipid complex loaded with fenticonazole nitrate for topical management of Candida Albicans

Preparation and characterization of solid lipid nanoparticles phospholipid complex loaded with fenticonazole nitrate for topical management of Candida Albicans

Synthesis, characterization and biological studies of transition metal complexes of dehydroacetic acid Schiff bases derived from 3-aminomethyl pyridine

The solid metal complexes of Cu (II), Ni (II), Fe (III), Co (II), Mn (II) and Cd (II) with DHA Schiff base ligand derived from DHA and aromatic primary amine 3-aminomethyl pyridine were synthesized and characterized by elemental analysis, spectroscopic techniques (FTIR, UV-VIS, 1HNMR and XRD), magnetic susceptibility measurement, thermogravimetric analysis and differential thermal analysis (TGA/DTA) and investigated for biological activities like anti-bacterial, ant-fungal, antioxidant and anticancer activity. The structure of synthesized DHA Schiff base ligand and all metal complexes were confirmed by spectroscopic methods, stability of complexes was studied by TGA/DTA. DHA Schiff base ligand and all metal complexes were found to be biologically active.

Synergistic effects of β-Cyclodextrin derivative inclusion complexes with favipiravir to enhance solubility and antiviral efficacy against Herpes Simplex virus type 1 (HSV-1)

In this study, the formation of β-cyclodextrin derivatives (β-Cyclodextrin; β-CD, Hydroxypropyl-β-Cyclodextrin; Hβ-CD, and Sulfobutylether-β-Cyclodextrin; Sβ-CD) inclusion complexes with favipiravir (FPR) was confirmed using various spectroscopic and analytical techniques. These complexes were shown to enhance FPR solubility and antiviral activity against herpes simplex virus type 1 (HSV-1). UV–visible and fluorescence spectroscopy revealed a continuous increase in FPR absorbance and fluorescence intensity with increasing β-CD concentrations, indicating the successful formation of 1:1 inclusion complexes. The prepared β-CD solid complexes were characterized using FTIR, XRD, FESEM, and TGA-DSC, which highlighted significant surface properties, morphological changes, and improved thermal stability. Phase solubility studies demonstrated enhanced FPR solubility in the presence of the β-CDs, with stability constants (Ks) following the order: Hβ-CD (694.8 M−1) > Sβ-CD (418.4 M−1) > β-CD (364.3 M−1). In-vitro release studies showed that the Hβ-CD complex achieved a higher cumulative release of 90.16 ± 1.94 % over 90 min compared to free FPR (25.32 ± 0.29 %), attributed to its greater solubility. Molecular docking provided insights into the interaction mechanisms, revealing higher binding affinities and stability for FPR with β-CD. In-vitro antiviral assays against HSV-1 demonstrated significant viral titer reductions for free FPR with β-CDs, with Hβ-CD outperforming others due to its rapid release profile after 96 h of incubation, confirming its potential for improved antiviral formulations. The cytotoxic effects of FPR and its β-CDs inclusion complexes were evaluated on Vero cells using an MTT assay over 96 h, showing reduced cytotoxicity for the inclusion complexes compared to free FPR. Additionally, cellular uptake studies revealed that β-CDs inclusion complexes conjugated with DAPI and FITC exhibited greater intensity within Vero cells compared to free FPR.

Randomly methylated β-cyclodextrin improves water – solubility, cellular protection and mucosa permeability of idebenone

Neurodegenerative diseases such as Alzheimer’s are very common today. Idebenone (IDE) is a potent antioxidant with good potential for restoring cerebral efficiency in cases of these and other medical conditions, but a serious drawback for the clinical use of IDE in neurological disorders lies in its scarce water solubility, which greatly inhibits its bioavailability. In this work, we prepared the inclusion complex of IDE with randomly methylated β-cyclodextrin (RAMEB), resulting in improved water solubility of the included drug; then its in vitro biological activity and ex vivo permeability was evalutated. The solid complex was characterized through FT-IR spectroscopy, Thermogravimetric analysis (TGA) and Differential Scanning Calorimetry (DSC). A 78-fold improvement of the solubility of IDE in water resulted, together with a strong 1:1 host–guest interaction (association constant of 12630 M−1), and dissolution of the complex within 15 min, all evidenced during the in-solution studies. Biological in vitro studies were then performed on differentiated human neuroblastoma cells (SH-SY5Y) subjected to oxidative stress. Pretreatment with IDE/RAMEB positively affected cell viability, promoted the nuclear translocation of Nrf2, and increased the levels of GSH as well as those of the endogenous antioxidant enzymes Mn-SOD and HO-1. Lastly, the complexation significantly improved the permeation of IDE through isolated rat nasal mucosa.

Effects of alkali-soluble hemicellulose separation on the structure of bamboo lignin and lignin-carbohydrate complexes

In this study, alkali treatment was used to preferentially separate hemicellulose, and the structural changes of lignin and lignin-carbohydrate complexes (LCC) in the residual bamboo solids were investigated. The chemical composition and structural characteristics of lignin and LCC were analyzed. After alkali treatment, the monosaccharide content in bamboo lignin decreased from 7.62 % to 2.90 % compared to the raw material. The obtained lignin exhibited higher purity and larger molecular weight, with the macromolecular lignin linked by β-O-4′ bonds remaining almost undegraded. After alkali treatment, the linkage bonds in the Björkman LCC were composed of phenyl glycoside (PhGlc), and the bond in LCC-AcOH consisted of benzyl ether (BE). The results showed that the preferential extraction of hemicellulose preserved the biopolymer structure of lignin in bamboo, thereby providing an important basis for the comprehensive separation and utilization of bamboo components.

Ultra-high areal capacity, ultra-long life, dendrite-free sodium metal anode enabled by antimony-based Na-ion conducting artificial SEI layers

Sodium metal (Na) is a promising anode material for Na metal batteries and solid-state sodium batteries, because of its high theoretical capacity, favorable electrochemical potential, and cost effectiveness. Nevertheless, practical applications of sodium metal anode are hindered by uncontrolled dendrite growth owing to chemical instability of the heterogeneous solid electrolyte interphase layer. In this work, we proposed a simple interface modification strategy employing several antimony-based Na-ion conducting solid electrolyte complexes as protective artificial SEI layer over Na metal. The Na-ion conducting interphases are robust and highly Na-ion conductive to attain uniform sodium ion flux with a small overpotential. Importantly, Na anode with antimony sulfide based solid electrolyte SEI layers exhibited the high-rate performance (10 mA cm−2) along with a remarkable capacity of 30 mAh cm−2, and life span of ∼ 1100 h. We observe that replacing the conventional artificial SEI layers, employing alloy type interface with Na-ion conducting solid electrolyte as artificial SEI components will improve the mechanical robustness at high current and high-capacity conditions. The sodium metal batteries employing modified metal anodes and high voltage Na1.2Mn0.8O1.5F0.5 cathode, exhibited excellent stability and high efficiency at 1C rate. Furthermore, the modified metal anodes are well-compatible with Na3SbS4 solid-state electrolyte, and the symmetrical solid-state battery exhibited a stable interface. Our strategy holds significant promise and has the potential for widespread application in theadvancement of high-energy sodium metal batteries and solid-state sodium batteries.

The Hydrogen-Bond Continuum in the Salt/Cocrystal Systems of Quinoline and Chloro-Nitrobenzoic Acids.

This study investigates the hydrogen-bond geometry in six two-component solid systems composed of quinoline and chloro-nitrobenzoic acids. New X-ray diffraction studies were conducted using both the conventional independent-atom model and the more recent Hirshfeld atom-refinement method, with the latter providing precise hydrogen-atom positions. The systems can be divided into salts (the hydrogen atom transferred to the quinoline nitrogen), cocrystals (the hydrogen atom retained by the acid), and intermediate structures. Solid-state NMR experiments corroborated the X-ray diffraction-derived H-N distances. DFT calculations, using five functionals including hybrid B3LYP and PBE0, showed varying energy profiles for the hydrogen bonds, with notable differences across functionals. These calculations revealed different preferences for salt or cocrystal structures, depending on the functional used. Path-integral molecular dynamics simulations incorporating nuclear quantum effects demonstrated significant hydrogen-atom delocalization, forming a hydrogen-bond continuum, and provided average N-H distances in excellent agreement with experimental results. This comprehensive experimental and theoretical approach highlights the complexity of multicomponent solids. The study emphasizes that the classification into salts or cocrystals is frequently inadequate, as the hydrogen atom is often significantly delocalized in the hydrogen bond. This insight is crucial for understanding and predicting the behavior of such systems in pharmaceutical applications.

Structural and antibacterial assessment of two distinct dihydroxy biphenyls encapsulated with β-cyclodextrin supramolecular complex

β-Cyclodextrin plays a vital role in biological application because it can enhance the stability and solubility of the guest molecules in the supramolecular inclusion complexes. Moreover, the β-Cyclodextrin inclusion complex has control-releasing behavior and lower toxicity than bare guest molecules. To improve the solubility and stability properties of two structurally different fluorescent guest molecules, namely 2,2′-dihydroxy biphenyl and 3,3′-dihydroxy biphenyls, they involve the β-Cyclodextrin inclusion complex process. Optical measurements clearly described the efficient binding through the changes in the absorbance and emission intensities of guest molecules in the presence of β-Cyclodextrin. The Job's plot from absorbance measurements reveals the 1:1 stochiometric ratio of binding of guests and the β-Cyclodextrin host. The FT-IR spectra of the solid complex show the characteristic stretching and bending vibrations from both the guests and the host molecule. The 1HNMR spectra of the inclusion complex promote downfield shifting of guest molecule protons upon binding with the β-Cyclodextrin host. The solid complex prepared using the solution method exhibits superior antibacterial activity against both gram-positive and gram-negative bacteria compared to the kneading and physical mixing methods.

A Versatile Redox-Active Electrolyte for Solid Fixation of Polyiodide and Dendrite-Free Operation in Sustainable Aqueous Zinc-Iodine Batteries.

Practical utilization of zinc-iodine (Zn-I2) batteries is hindered by significant challenges, primarily stemming from the polyiodide shuttle effect on the cathode and dendrite growth on the anode. Herein, a feasible redox-active electrolyte has been introduced with tetraethylammonium iodide as an additive that simultaneously addresses the above mentioned challenges via polyiodide solidification on the cathode and the electrostatic shielding effect on the anode. The tetraethylammonium (TEA+) captures water-soluble polyiodide intermediates (I3 -, I5 -), forming a solid complex at the cathode, thereby suppressing capacity loss during charge/discharge. Furthermore, the TEA+ mitigates dendrite growth on the Zn anode via the electrostatic shielding effect, promoting uniform and compact Zn deposition at the anode. Consequently, the Zn||Zn symmetric cell demonstrates superior cycling stability during Zn plating/stripping over 4,200h at 1mA cm-2 and 1 mAh cm-2. The Zn||NiNC full-cell exhibits a stable capacity retention of 98.4% after 20000 cycles (>5 months) with near-unity Coulombic efficiency at 1 A g-1. The study provides novel insights for establishing a new direction for low-cost, sustainable, and long-lifespan Zn-I2 batteries.

New nano-complexes targeting protein 3S7S in breast cancer and protein 4OO6 in liver cancer investigated in cell line

Cancer, a lethal ailment, possesses a multitude of therapeutic alternatives to combat its presence, metal complexes have emerged as significant classes of medicinal compounds, exhibiting considerable biological efficacy, especially as anticancer agents. The utilization of cis-platin in the treatment of various cancer types, including breast cancer, has served as inspiration to devise novel nanostructured metal complexes for breast cancer therapy. Notably, homo- and hetero-octahedral bimetallic complexes of an innovative multifunctional ether ligand (comprising Mn(II), Ni(II), Cu(II), Zn(II), Hg(II), and Ag(I) ions) have been synthesized. To ascertain their structural characteristics, elemental and spectral analyses, encompassing IR, UV–Vis, 1H-NMR, mass and electron spin resonance (ESR) spectra, magnetic moments, molar conductance, thermal analysis, and electron microscopy, were employed. The molar conductance of these complexes in DMF demonstrated a non-electrolytic nature. Nanostructured forms of the complexes were identified through electron microscopic data. At ambient temperature, the ESR spectra of the solid complexes exhibited anisotropic and isotropic variants, indicative of covalent bonding. The ligand and several of its metal complexes were subjected to cytotoxicity testing against breast cancer protein 3S7S and liver cancer protein 4OO6, with the Ag(I) complex (7) evincing the most potent effect, followed by the Cu(II) with ligand (complex (2)), Cis-platin, the ligand itself, and the Cu(II)/Zn(II) complex (8). Molecular docking data unveiled the inhibitory order of several complexes.

Novel metal chelates with antipyrine tridentate azo dye ligand for antimicrobial and antitumor applications: Synthesis, structure affirmation, DFT studies, and molecular docking simulation

Novel azo dye ligand [4‐([2,3‐dimethyl‐5‐oxo‐1‐phenyl‐2,5‐dihydro‐1H‐pyrazol‐4‐yl]diazenyl)‐3‐hydroxybenzaldehyde (HL)] and its Co(II), Ni(II), Ru(III), and Zr(IV) metal chelates, were produced and thoroughly described applying modern spectral and analytical approaches. The results showed that HL chelated in tridentate mode, leading to octahedral geometry toward the present metal ions where Co(II), Ni(II), and Zr(IV) complexes exhibit outer sphere hybridization, while the Ru(III) complex exhibits inner sphere hybridization. The calculated particle size values of the complexes reached 41.34, 46.41, 48.67, and 33.37 nm for Co(II), Ni(II), Ru(III), and Zr(IV) chelates, respectively applying the Debye–Scherrer equation on XRD patterns. When compared to its metal complexes, the ligand's antibacterial action against several bacteria demonstrates increased activity. Tests were conducted on A‐549 and PANC‐1 cells to evaluate the compounds' anticancer efficacy against the vinblastine standard. Co(II) nanosized complex exhibited cytotoxicity that was greater than that of the reference medication vinblastine sulfate against A‐549 cell line. It is promising to use the Co(II) complex to create novel anticancer medications. Quantum chemical calculations for ligand and its solid metal complexes were carried out utilizing the DFT of the DMOL3 module. Furthermore, the molecular docking studies were conducted on the A‐549 protein, associated with FGFR1, using the Schrödinger suite. The ligand and the Ru(III) complex exhibit the most potent inhibitory effects on the FGFR1 protein, a receptor tyrosine kinase integral to cellular growth and differentiation.

Solution studies, synthesis and antibacterial activity of Ga(III) complexes with bis-kojate derivatives

Given the recognized major problem of microbial drug resistance for human health, new metal-based drugs have been currently explored for their antimicrobial properties, including gallium-based compounds as potential metallophores that could perturb Fe’s interactions with proteins. Herein we have designed and synthesized two bis-kojate ligands (named L4 and L6) and studied their Ga(III) complexes for their physico-chemical and biological properties. In particular a detailed study of their complexation properties in aqueous solution, showed equilibrium models with formation of quite stable dinuclear 2:3 metal:ligand complexes, though with different stability. Solid state complexes were also prepared and characterized and complementary DFT studies indicated that [Ga2(L4)3] complex, with higher stability, seems to adopt a three-ligand bridging conformation, while that for L6 adopt a one ligand bridging conformation. Preliminary investigation of the antibacterial activity of these gallium complexes showed antipseudomonal activity, which appeared higher for the complex with L4, a feature of potential interest for the scientific community.

Enrofloxacin Pharmaceutical Formulations through the Polymer-Free Electrospinning of β-Cyclodextrin-oligolactide Derivatives.

Enrofloxacin (ENR), a member of the fluoroquinolone class of antibiotics, is widely used in veterinary medicine to treat bacterial infections. Like many antibiotics, ENR has limited water solubility and low bioavailability. To address these challenges, drug formulations using solid dispersions, nanosuspensions, surfactants, cocrystal/salt formation, and inclusion complexes with cyclodextrins may be employed. The approach described herein proposes the development of ENR formulations by co-electrospinning ENR with custom-prepared cyclodextrin-oligolactide (CDLA) derivatives. This method benefits from the high solubility of these derivatives, enabling polymer-free electrospinning. The electrospinning parameters were optimized to incorporate significant amounts of ENR into the CDLA nanofibrous webs, reaching up to 15.6% by weight. The obtained formulations were characterized by FTIR and NMR spectroscopy methods and evaluated for their antibacterial activity against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. This study indicates that the presence of CDLA derivative does not inhibit the antibacterial activity of ENR, recommending these formulations for further development.

Preparation and Evaluation of Berberine-Excipient Complexes in Enhancing the Dissolution Rate of Berberine Incorporated into Pellet Formulations

Berberine is used in the treatment of metabolic syndrome and its low solubility and very poor oral bioavailability of berberine was one of the primary hurdles for its market approval. This study aimed to improve the solubility and bioavailability of berberine by preparing pellet formulations containing drug-excipient complex (obtained by solid dispersion). Berberine-excipient solid dispersion complexes were obtained with different ratios by the solvent evaporation method. The maximum saturation solubility test was performed as a key factor for choosing the optimal complex for the drug-excipient. The properties of these complexes were investigated by FTIR, DSC, XRD and dissolution tests. The obtained pellets were evaluated and compared in terms of pelletization efficiency, particle size, mechanical strength, sphericity and drug release profile in simulated media of gastric and intestine. Solid-state analysis showed complex formation between the drug and excipients used in solid dispersion. The optimal berberine-phospholipid complex showed a 2-fold increase and the optimal berberine-gelucire and berberine-citric acid complexes showed more than a 3-fold increase in the solubility of berberine compared to pure berberine powder. The evaluation of pellets from each of the optimal complexes showed that the rate and amount of drug released from all pellet formulations in the simulated gastric medium were significantly lower than in the intestine medium. The results of this study showed that the use of berberine-citric acid or berberine-gelucire complex could be considered a promising technique to increase the saturation solubility and improve the release characteristics of berberine from the pellet formulation.Graphical

Integrative approach for improved dofetilide solubility using β-cyclodextrin and two its substituted derivatives: Solutions and solid dispersions

The complexation an anti-arrhythmia drug dofetilide (DFT) with β-cyclodextrin (β-CD), 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) and sulfobutylether-β-cyclodextrin (SBE-β-CD) were studied using two main approaches: phase solubility diagrams and solid dispersions technique. The phase solubility diagrams were constructed in buffer solutions with physiological values рН 2.0 и 7.4. In accordance with the protolytic properties of the drug, the solubilizing effect of cyclodextrins turned out to be more effective in a neutral environment (buffer pH 7.4): the solubility improvement of DFT in the presence of β-CD, HP-β-CD and SBE-β-CD was 3.6, 11.8 and 18.1 times, respectively. In buffer pH 2.0, the tendency for an increase in the solubilizing effect, depending on the chemical nature of the CDs used, is maintained, but the solubility of the drug almost does not grow. The binding constants for the DFT/HP-β-CD and DFT/SBE-β-CD complexes equal to 344 L·mol−1 and 429 L·mol−1 in buffer pH 7.4 indicate the formation of stable inclusion complexes and belong to the optimal range for refinement bioavailability and stability of hydrophobic drugs. Amorphous solid dispersions DFT/β-CD, DFT/HP-β-CD and DFT/SBE-β-CD with stoichiometry 1:1 were obtained by grinding method. The combination FTIR, PXRD, DSC, TGA and SEM methods confirmed the inclusion complexes formation of the drug with cyclodextrins used. Dissolution profiles of solid dispersions DFT/β-CD, DFT/HP-β-CD and DFT/SBE-β-CD were graphing in buffer solutions рН 2.0 and 7.4. Enlargement factor of DFT solubility in the composition of solid dispersions DFT/β-CD, DFT/HP-β-CD and DFT/SBE-β-CD in the neutral medium are 3.4, 4.1 and 5.2, respectively. Whereas the formation of solid inclusion complexes DFT/CDs in an acidic buffer has virtually no effect on the increase in the equilibrium concentration of the active substance in the solution. Findings have demonstrated that the use of SBE-β-CD shows the best solubilization potential for DFT both in solution and as a solid dispersion.

Potential of Native Cyclodextrins and L-Lysine for Enhancing Ellagic Acid Aqueous Solubility

This study aimed to examine the influence of β cyclodextrin (βCD) and γ cyclodextrin (γCD) alone and in combination with L-lysine on ellagic acid (EA) solubility. Indeed, complexation with cyclodextrins can be used to improving the solubility of drugs poorly soluble in water such as EA. EA is a Biopharamceutical Classification System (BCS) IV bioactive polyphenol with numerous therapeutic activities, including antimalarial activities. However, its unfavorable physicochemical properties limit its therapeutic use. Therefore, after a phase solubility study, we successfully prepared EA-βCD and γ CD binary solid complexes using the freeze-drying technique. Methods including proton nuclear magnetic resonance (1H-NMR) analysis and fourier-transform infrared (FTIR) spectroscopy were used to characterize the inclusion behaviors of the complexes of EA with cyclodextrins both in solution and solid forms. The results of the phase solubility study indicated Ap-type diagrams of EA with the two cyclodextrins (CDs). The solubility of EA was multiplied by 9.92 and 2.98 in the presence of γCD and βCD respectively. Moreover, the complexes characterization by FTIR spectroscopy revealed the involvement of the C=O and EA OH groups in the interaction with the CDs. The results of NMR spectroscopic characterization revealed that the formation of EA inclusion complexes with βCD was partial. However, these results did not indicate the appearance of EA inclusion complexes with γCD. These relatively modest results in terms of increased EA solubility, obtained with cyclodextrins, prompted us to use a third compound, l-lysine, to enhance CDs complexation. Thus, the formation of ternary complexes led to a very significant increase EA solubility. Indeed, the incorporation of EA into EA-L-lysine-βCD and γ CD complexes increased its water solubility at pH 7.4 by a factor of 555 and 663, respectively.

Impacto e desafios da presença de animais silvestres no saneamento rural

In this article, we will explore the complex interaction between wild animals and rural sanitation, highlighting the different aspects of this relationship and analyzing its implications. Rural sanitation is a crucial area to ensure the health and well-being of communities living outside urban centers. Encompassing a variety of activities and infrastructure, rural sanitation aims to provide safe access to drinking water, adequate sewage treatment and effective solid waste management. The relationship between rural sanitation and wild animals is close and their interactions can have significant consequences for both public health and the preservation of fauna. While rural sanitation seeks to ensure safe access to drinking water, effective sewage treatment and adequate solid waste management, the presence of wild animals can introduce additional challenges to these initiatives. The influence of wild animals in the context of rural sanitation is a crucial factor to be addressed to promote public health and environmental sustainability in rural communities. Although these animals perform essential functions in natural ecosystems, their presence can pose significant challenges to sanitation practices, such as contamination of drinking water sources, inadequate management of solid waste and complexity in sewage treatment.

Exploring microstructures of metal-doped oxides via simulated Raman spectrum

Solid solution of metal-doped oxide has been widely used in material industry and catalysis process. Its performance is highly correlated with the distribution of doped ions. Due to the complex distribution of doped ions in solid solution and its variation with temperatures, to obtain the microstructures of metal-doped ions in solid solution remains a substantial challenge. Taken Ce1-xZrxO2 as a model, the global structure searching, structures proportion with temperature determined by Boltzmann distribution, and the weighted simulation Raman spectra were integrated to explore the microstructures of metal-doped solid solution oxides. It was further verified by application into rutile and anatase TiO2 mixture, indicating that the present method is feasible to deduce the microstructure of metal composite oxides. We anticipate that it provides a powerful solution to explore microstructures of solid solution and complex metal oxides.